Devices powered by replaceable or rechargeable batteries generally include one or more battery holders configured to hold the batteries and make electrical contact with the batteries. In such devices, proper installation of the batteries is commonly achieved through the use of written or graphical directions that indicate the proper battery orientation for correct electrical polarity. Users often follow such instructions correctly, but at times the graphics may be difficult to see as they may have been molded directly into or as part of the product housings, or the directions may have been printed on small or difficult-to-read labels. As a result, users occasionally may incorrectly install batteries with reversed electrical polarity.
Installing batteries with reversed polarity may cause battery problems and product damage. In the best case, the product may simply not work. In worse cases, batteries may overhead and leak, which may cause permanent damage to the electronics, and also may lead to safety problems.